Embodiments of the inventive concept described herein relate to an apparatus and a method for supplying a liquid.
To fabricate a semiconductor device, various processes, such as a photolithography, etching, ashing, and rinsing processes are performed. The processes are to supply the liquid to a substrate and an amount of the liquid to be supplied is varied depending on the processes.
In general, an apparatus for supplying a liquid supplies the liquid in amount set depending on processes or processing steps. The amount of the liquid is adjusted based on the supply pressure of the liquid. In general, the supply pressure of the liquid is adjusted by a constant pressure valve. FIG. 1 is a sectional view illustrating a conventional constant pressure valve. Referring to FIG. 1, the constant pressure valve includes a body having a fluid passage through which the liquid flows and a diaphragm movable in the fluid passage. The diaphragm is moved by the pressure of the fluid passage.
As the liquid is supplied, the pressure of the fluid passage is lowered and the diaphragm is moved such that the fluid passage is open. In contrast, when the supply of the liquid is stopped, the pressure of the fluid passage is increased and the diaphragm is moved such that the fluid passage is closed.
However, at the time point that the supply of the liquid is stopped, collision may occur between the body and the diaphragm. The discharge and the stop of the liquid are repeatedly performed several hundreds of times to several thousands of times when multiple sheets of substrates are treated. Accordingly, the collision between the body and the diaphragm is repeated, and a large amount of particles are produced during the collision.
These particles are supplied to the substrate together with the liquid to contaminate the substrate and to cause the process failure.